What is a geomagnetic storm?
The correct answer is D: A temporary disturbance in Earth's geomagnetic field. A geomagnetic storm is a temporary disturbance in Earth's geomagnetic field. These storms are caused by charged particles from the Sun interacting with Earth's magnetic field. For amateur radio operators, geomagnetic storms can disrupt HF propagation, especially at high latitudes. Understanding this helps explain propagation disruptions.
Exam Tip
Geomagnetic storm = temporary disturbance in Earth's geomagnetic field. Think 'G'eomagnetic 'S'torm = 'G'eomagnetic 'S'ignificant disturbance. Temporary disturbance in Earth's magnetic field caused by solar particles. Not solar flux drop, not thunderstorms, not just ripples - significant magnetic disturbance.
Memory Aid
"Geomagnetic storm = temporary disturbance in Earth's geomagnetic field. Think 'G'eomagnetic 'S'torm = 'G'eomagnetic 'S'ignificant disturbance. Temporary disturbance caused by solar particles interacting with Earth's magnetic field. Can disrupt HF propagation."
Real-World Application
A coronal mass ejection from the Sun sends charged particles toward Earth. When they arrive, they interact with Earth's magnetic field, causing a geomagnetic storm - a temporary disturbance in the geomagnetic field. This can disrupt HF propagation, especially at high latitudes, and can create auroras. The disturbance is temporary but can last hours or days.
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. Geomagnetic storms aren't a drop in solar flux - they're disturbances in Earth's magnetic field, not solar flux changes.
Option B: Incorrect. Geomagnetic storms aren't thunderstorms - they're magnetic field disturbances, not weather. Different phenomenon.
Option C: Incorrect. Geomagnetic storms aren't just 'ripples' - they're significant temporary disturbances that can disrupt propagation. 'Ripples' understates their impact.
题目解析
The correct answer is D: A temporary disturbance in Earth's geomagnetic field. A geomagnetic storm is a temporary disturbance in Earth's geomagnetic field. These storms are caused by charged particles from the Sun interacting with Earth's magnetic field. For amateur radio operators, geomagnetic storms can disrupt HF propagation, especially at high latitudes. Understanding this helps explain propagation disruptions.
考试技巧
Geomagnetic storm = temporary disturbance in Earth's geomagnetic field. Think 'G'eomagnetic 'S'torm = 'G'eomagnetic 'S'ignificant disturbance. Temporary disturbance in Earth's magnetic field caused by solar particles. Not solar flux drop, not thunderstorms, not just ripples - significant magnetic disturbance.
记忆口诀
Geomagnetic storm = temporary disturbance in Earth's geomagnetic field. Think 'G'eomagnetic 'S'torm = 'G'eomagnetic 'S'ignificant disturbance. Temporary disturbance caused by solar particles interacting with Earth's magnetic field. Can disrupt HF propagation.
实际应用示例
A coronal mass ejection from the Sun sends charged particles toward Earth. When they arrive, they interact with Earth's magnetic field, causing a geomagnetic storm - a temporary disturbance in the geomagnetic field. This can disrupt HF propagation, especially at high latitudes, and can create auroras. The disturbance is temporary but can last hours or days.
错误选项分析
Option A: Incorrect. Geomagnetic storms aren't a drop in solar flux - they're disturbances in Earth's magnetic field, not solar flux changes. Option B: Incorrect. Geomagnetic storms aren't thunderstorms - they're magnetic field disturbances, not weather. Different phenomenon. Option C: Incorrect. Geomagnetic storms aren't just 'ripples' - they're significant temporary disturbances that can disrupt propagation. 'Ripples' understates their impact.
知识点
Geomagnetic storm, Earth's magnetic field, Temporary disturbance, Propagation effects
Verified Content
Question from official FCC General Class question pool. Explanation reviewed by licensed amateur radio operators.